When the travel agency that booked a group of 45 NYU students on a charter flight to Cuba folded three days before the trip, Lizet Gediciyan at Travelcraft was able to rebook the entire trip -- non-charter -- at a cheaper rate. The agency has many tricks up its sleeve, like waving advance-purchase fares and hounding airlines until they find a seat for you, even during holiday time. Alternatively, Frenchway (11 West 25th Street; 212-243-3500) caters to models, so they’re used to capricious types who change plans at the last moment. They’ll go that extra mile -- once even sending a dress solo to a shoot in Paris via London because there were no direct flights left. The best part: They work seven days a week, and are always available via beeper.